PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

Silk microneedles deliver controlled-release drugs painlessly

2011-12-22
(Press-News.org) MEDFORD/SOMERVILLE, Mass. -- Bioengineers at Tufts University School of Engineering have developed a new silk-based microneedle system able to deliver precise amounts of drugs over time and without need for refrigeration. The tiny needles can be fabricated under normal temperature and pressure and from water, so they can be loaded with sensitive biochemical compounds and maintain their activity prior to use. They are also biodegradable and biocompatible.

The research paper "Fabrication of Silk Microneedles for Controlled-Release Drug Delivery" appeared in Advanced Functional Materials December 2 online in advance of print.

The Tufts researchers successfully demonstrated the ability of the silk microneedles to deliver a large-molecule, enzymatic model drug, horseradish peroxidase (HRP), at controlled rates while maintaining bioactivity. In addition, silk microneedles loaded with tetracycline were found to inhibit the growth of Staphylococcus aureus, demonstrating the potential of the microneedles to prevent local infections while also delivering therapeutics.

"By adjusting the post-processing conditions of the silk protein and varying the drying time of the silk protein, we were able to precisely control the drug release rates in laboratory experiments," said Fiorenzo Omenetto, Ph.D., senior author on the paper. "The new system addresses long-standing drug delivery challenges, and we believe that the technology could also be applied to other biological storage applications."

The Drug Delivery Dilemma

While some drugs can be swallowed, others can't survive the gastrointestinal tract. Hypodermic injections can be painful and don't allow a slow release of medication. Only a limited number of small-molecule drugs can be transmitted through transdermal patches. Microneedles—no more than a micron in size and able to penetrate the upper layer of the skin without reaching nerves—are emerging as a painless new drug delivery mechanism. But their development has been limited by constraints ranging from harsh manufacturing requirements that destroy sensitive biochemicals, to the inability to precisely control drug release or deliver sufficient drug volume, to problems with infections due to the small skin punctures.

The process developed by the Tufts bioengineers addresses all of these limitations. The process involves ambient pressure and temperature and aqueous processing. Aluminum microneedle molding masters were fabricated into needle arrays of about 500 µm needle height and tip radii of less than 10 µm. The elastomer polydimethylsiloxane (PDMS) was cast over the master to create a negative mold; a drug-loaded silk protein solution was then cast over the mold. When the silk was dry, the drug-impregnated silk microneedles were removed. Further processing through water vapor annealing and various temperature, mechanical and electronic exposures provided control over the diffusity of the silk microneedles and drug release kinetics.

"Changing the structure of the secondary silk protein enables us to 'pre-program' the properties of the microneedles with great precision," said David L. Kaplan, Ph.D., coauthor of the study, chair of biomedical engineering at Tufts and a leading researcher on silk and other novel biomaterials. "This is a very flexible technology that can be scaled up or down, shipped and stored without refrigeration and administered as easily as a patch or bandage. We believe the potential is enormous."

###Other co-authors on the paper, all associated with the Department of Biomedical Engineering, are Konstantinos Tsioris, doctoral student; Waseem Raja, post-doctoral associate; Eleanor Pritchard, post-doctoral associate; and Bruce Panilaitis, research assistant professor.

The research was based on work supported in part by the U.S. Army Research Laboratory, the U.S. Army Research Office, the Defense Advanced Research Projects Agency-Defense Sciences Office and the Air Force Office of Scientific Research.

Tsioris, K., Raja, W. K., Pritchard, E. M., Panilaitis, B., Kaplan, D. L. and Omenetto, F. G. (2011), Fabrication of Silk Microneedles for Controlled-Release Drug Delivery. Advanced Functional Materials. doi: 10.1002/adfm.201102012

Located on Tufts' Medford/Somerville campus, the School of Engineering offers a rigorous engineering education in a unique environment that blends the intellectual and technological resources of a world-class research university with the strengths of a top-ranked liberal arts college. Close partnerships with Tufts' undergraduate, graduate and professional schools, coupled with a long tradition of collaboration, provide a strong platform for interdisciplinary education and scholarship. The School of Engineering's mission is to educate engineers committed to the innovative and ethical application of science and technology in addressing the most pressing societal needs, to develop and nurture twenty-first century leadership qualities in its students, faculty, and alumni, and to create and disseminate transformational new knowledge and technologies that further the well-being and sustainability of society in such cross-cutting areas as human health, environmental sustainability, alternative energy, and the human-technology interface.


ELSE PRESS RELEASES FROM THIS DATE:

To Spank or Not to Spank: Should the Government Have a Say?

2011-12-22
It's no surprise that disputes between divorced couples can get ugly, especially when children are involved. But what happens when one parent begins making questionable domestic violence allegations? WTSP, a CBS affiliate in Tampa Bay, recently reported on a case where a woman accused her former husband of domestic violence for administering a single spank as punishment to their 14 year old daughter. Domestic Violence and Florida Law Domestic violence is a term defined by Florida Statute to include any assault, battery, stalking, kidnapping, false imprisonment or ...

JAMA commentary contends vitamin therapy can still reduce stroke

2011-12-22
A commentary by Dr. David Spence of The University of Western Ontario and Dr. Meir Stampfer of the Harvard School of Public Health in today's Journal of the American Medical Association (JAMA) argues that vitamin therapy still has a role to play in reducing stroke. Vitamin B therapy was once widely used to lower homocysteine levels. Too much of this amino acid in the bloodstream was linked to increased risk of stroke and heart attack. But several randomized trials found lowering homocysteine levels with B vitamins did not result in a cardiovascular benefit. And a ...

The mall as a sanctuary: Study finds holiday shopping outlets aren't just shrines to spending

2011-12-22
An international study of holiday shopping and religion finds that dominant religious groups are more likely to experience "consumption mass hysteria" while shoppers in minority religions may view malls and stores much differently: as central meeting places that "can play an active role in the creation of a sacred event." The study, co-authored by Temple University Fox School of Business marketing professor Ayalla Ruvio, found that holiday consumption in dominant religious settings – such as Christians in the U.S. or Jews in Israel – can lead to greater frenzy and a "social ...

Brooklyn Premises Liability Lawsuits

2011-12-22
New York law requires property owners to ensure the safety of people on their land or in their buildings. This duty generally requires owners to keep their property safe and well-maintained. If a hazard is unavoidable -- such as a large hole in the ground during construction -- the owner must take steps to prevent people from being harmed by the danger. At Simon Eisenberg & Baum, our Brooklyn personal injury attorneys use our experience and knowledge to successfully litigate Brooklyn premises liability claims. It does not matter how obvious the fault of the property ...

Study examines how diving marine mammals manage decompression

2011-12-22
Any diver returning from ocean depths knows about the hazard of decompression sickness (DCS) or "the bends." As the diver ascends and the ocean pressure decreases, gases that were absorbed by the body during the dive, come out of solution and, if the ascent is too rapid, can cause bubbles to form in the body. DCS causes many symptoms, and its effects may vary from joint pain and rashes to paralysis and death. But how do marine mammals, whose very survival depends on regular diving, manage to avoid DCS? Do they, indeed, avoid it? In April 2010, the Woods Hole Oceanographic ...

Do you hear what I hear? Noise exposure surrounds us

2011-12-22
ANN ARBOR, Mich.---Nine out of 10 city dwellers may have enough harmful noise exposure to risk hearing loss, and most of that exposure comes from leisure activities. Historically, loud workplaces were blamed for harmful noise levels. But researchers at the University of Michigan found that noise from MP3 players and stereo use has eclipsed loud work environments, said Rick Neitzel, assistant professor in the U-M School of Public Health and the Risk Science Center. Robyn Gershon, a professor with the Philip R. Lee Institute for Health Policy Studies, University of California, ...

Astronomers discover rare galaxy at dawn of time

Astronomers discover rare galaxy at dawn of time
2011-12-22
RIVERSIDE, Calif. – Astronomers, including the University of California, Riverside's Bahram Mobasher and his graduate student Hooshang Nayyeri, have discovered that one of the most distant galaxies known is churning out stars at a shockingly high rate. The researchers made the discovery using NASA's Spitzer and Hubble space telescopes. The blob-shaped galaxy, called GN-108036, is the brightest galaxy found to date at such great distances. The galaxy, which was discovered and confirmed using ground-based telescopes, is 12.9 billion light-years away. Data from Spitzer ...

The Radisson Blu Hotel, Bristol Announces the Appointment of a New General Manager

2011-12-22
The Radisson Blu Hotel, Bristol, part of the rapidly-expanding Rezidor Hotel Group, has appointed Christopher Peach as the General Manager of the Radisson Blu Hotel, Bristol. Christopher brings managerial experience and a range of other hospitality-related skills to the position. Christopher has an extensive background in the hospitality industry, spanning 23 years. Having started his career in 1987 as Commis Chef aboard the Queen Elizabeth II cruise liner, he has since held various management positions at different international hotel chains in South Africa, China, ...

Radisson Blu Schwarzer Bock Hotel, Wiesbaden Offers Per Diem Rate

2011-12-22
The Radisson Blu Schwarzer Bock Hotel, Wiesbaden is to offer a per diem rate due to a change in location of its headquarters. During the next two years the US Army Europe, the Seventh Army and the US Army Corps will move to Wiesbaden and the hotel is therefore looking forward to welcome them as guests. The per diem rate is a specific amount of money that an organization allows its employees to spend per day to cover living and travelling expenses in connection with work. It eliminates the need to create expense reports after their business trips. The introduction ...

Belize protected area boosting predatory fish populations

Belize protected area boosting predatory fish populations
2011-12-22
A 14-year study by the Wildlife Conservation Society in an atoll reef lagoon in Glover's Reef, Belize has found that fishing closures there produce encouraging increases in populations of predatory fish species. However, such closures have resulted in only minimal increases in herbivorous fish, which feed on the algae that smother corals and inhibit reef recovery. The findings will help WCS researchers in their search for new solutions to the problem of restoring Caribbean reefs damaged by fishing and climate change. The study appears in an online version of Aquatic ...

LAST 30 PRESS RELEASES:

New microfluidic device reveals how the shape of a tumour can predict a cancer’s aggressiveness

Speech Accessibility Project partners with The Matthew Foundation, Massachusetts Down Syndrome Congress

Mass General Brigham researchers find too much sitting hurts the heart

New study shows how salmonella tricks gut defenses to cause infection

Study challenges assumptions about how tuberculosis bacteria grow

NASA Goddard Lidar team receives Center Innovation Award for Advancements

Can AI improve plant-based meats?

How microbes create the most toxic form of mercury

‘Walk this Way’: FSU researchers’ model explains how ants create trails to multiple food sources

A new CNIC study describes a mechanism whereby cells respond to mechanical signals from their surroundings

Study uncovers earliest evidence of humans using fire to shape the landscape of Tasmania

Researchers uncover Achilles heel of antibiotic-resistant bacteria

Scientists uncover earliest evidence of fire use to manage Tasmanian landscape

Interpreting population mean treatment effects in the Kansas City Cardiomyopathy Questionnaire

Targeting carbohydrate metabolism in colorectal cancer: Synergy of therapies

Stress makes mice’s memories less specific

Research finds no significant negative impact of repealing a Depression-era law allowing companies to pay workers with disabilities below minimum wage

Resilience index needed to keep us within planet’s ‘safe operating space’

How stress is fundamentally changing our memories

Time in nature benefits children with mental health difficulties: study

In vitro model enables study of age-specific responses to COVID mRNA vaccines

Sitting too long can harm heart health, even for active people

International cancer organizations present collaborative work during oncology event in China

One or many? Exploring the population groups of the largest animal on Earth

ETRI-F&U Credit Information Co., Ltd., opens a new path for AI-based professional consultation

New evidence links gut microbiome to chronic disease outcomes

Family Heart Foundation appoints Dr. Seth Baum as Chairman of the Board of Directors

New route to ‘quantum spin liquid’ materials discovered for first time

Chang’e-6 basalts offer insights on lunar farside volcanism

Chang’e-6 lunar samples reveal 2.83-billion-year-old basalt with depleted mantle source

[Press-News.org] Silk microneedles deliver controlled-release drugs painlessly